In magnetic recording and reproducing, a magnetic storage medium typically in the form of a disk or tape is moved across a magnetic head or transducer assembly which interacts with the medium to write or read stored information such as digital data. Recording of the stored data is effected by current reversals through the windings of the write head while reproduction of the data is accomplished when a voltage is induced in the windings of the read head when a flux reversal traverses the gap of that head. These operations generate spray magnetic fields or leakage flux about the magnetic heads and particularly so when the rise times of the data pulses are short.
Some magnetic storage devices incorporate two magnetic heads either of which can be selected for reading or writing. An example is the streaming magnetic tape drive disclosed in application Ser. No. 386,048, filed June 7, 1982 and entitled "Magnetic Data Storage And Drive Apparatus", which application issued on Oct. 16, 1984 as U.S. Pat. No. 4,477,851 and is commonly assigned with the present application. In that drive, the heads are mounted side-by-side along the direction of tape movement with a close spacing between head gaps, for example, of the order of 0.6 to 0.7 inch (1.5-1.8 cm). By using dual read/write heads having essentially the same read, write and erase characteristics, a bidirectional read-after-write function with error detection is made possible. As a result of leakage flux, however, excessive "crosstalk" between the closely adjacent heads can occur during read-after-write operations.